The present invention relates to identification card printers used to print images on a surface of rigid or semi-rigid planar substrates. More particularly, the present invention relates to a roller support for use in a transport mechanism of an identification card printer that provides support for feed and guide rollers.
Identification card printers along with the aid of a computer are typically used to form identification cards by printing an image on a card substrate. The image generally includes a photograph and other information relating to the card holder, such as the card holder""s name, employee number, and other information. Such identification cards are used for many purposes, such as driver""s licenses, identification badges, etc. The image that is to be printed on the card by the identification card printer is generally formed by combining textual and graphical portions received from host applications running on the computer or from other input devices such as keyboards, scanners, and digital cameras. Data relating to the formatted image is then provided to the printer in the form of a print job. The printer processes the print job by printing the image onto a surface of the card.
Most identification card printers are thermal based printers that include a ribbon having primary colored dye panels and a thermal printhead. One type of thermal based printer is a dye sublimation printer, in which the thermal printhead heats the ribbon and causes dye on the colored panels to be released and sublimate into a surface of the card. Unfortunately, these printers are only compatible with cards having a specialized surface into which the dye can sublimate. Furthermore, these printers are generally incapable of providing full edge-to-edge printing due to problems caused by the ribbon adhering to the edges of the card. Another type of thermal based printer prints the image onto a film, which is subsequently laminated to the card. This type of thermal base printer has full edge-to-edge printing capability, which is achieved by printing an image onto the film that is larger than the surface of the card on which it is to be laminated. Unfortunately these printers are complex and often too expensive for small operations.
Another type of identification card printer is an ink jet based card printer. These printers are typically more affordable than thermal based printers and are somewhat less complicated. Ink jet card printers generally include an ink jet printhead and a transport mechanism. The ink jet printhead is designed to form the desired image on a surface of a card by spraying colored ink onto portions of the surface that are presented to the ink jet printhead in a print position by the transport mechanism.
Typical transport mechanisms include a platen positioned immediately below the printhead and rollers positioned adjacent the printhead that pinch the card against the platen as it is transported through the print position. Typical ink jet printers are generally incompatible with semi-rigid substrates. Instead, thin and highly flexible substrates must be used that can bend around the platen and other rollers of the transport mechanism as they are transported. Additionally, the rollers typically contact side portions of the surface of the card when in the print position thereby obstructing the surface of the card and preventing the ink jet printhead from printing on the surface in those locations. As a result, these types of ink jet card printers are incapable of full edge-to-edge printing on the card.
Even if the rollers of the transport mechanism were positioned such that the ink jet printhead would have the freedom to print, for example, from a side edge of the card to an opposing side edge, this type of printer is still prevented from printing edge-to-edge due to the contamination of the platen and other components of the transport mechanism that would result from springing beyond the edges of the card as would be required for full edge-to-edge printing on the card. In addition to potentially clogging the transport mechanism and causing the printer to fail, the resulting contaminated components of the transport mechanism would transfer the contaminating ink to the cards that are subsequently processed. As a result, most ink jet card printers are not suitable for full edge-to-edge printing and, instead, limit printing on the substrate to a smaller area defined by margins formed along the edges of the substrate.
Some ink jet card printers, however, include modified transport mechanisms that avoid some of the problems described above. These printers allow printing on surfaces of semi-rigid cards by adapting the transport mechanism to transport the cards through the printer in a tray. The trays generally include a depressed region that conforms to the shape of the card and exposes a top planar surface of the card on which an image is to be printed. Unfortunately, these printers are still unable to provide full edge-to-edge printing capability without contaminating the tray and other components of the transport mechanism.
There is a continuing need for improvements to identification card printers including improvements to transport mechanisms in order to provide full edge-to-edge printing capability, increased reliability and performance, and simplified manufacturing.
The present invention is directed to a roller support for use in a transport mechanism of an identification card printer. The roller support can be used to form single and/or dual pinch roller assemblies that can feed and support cards and allow for full edge-to-edge printing capability. The roller support includes a body member, a bushing member, and a step member. The body member includes a first guide roller receiver that is adapted to receive an end of a first guide roller. The bushing member extends from a surface of the body member and has a central bore that extends through the body member. The step member is positioned adjacent the bushing member and extends from the surface of the body member in the direction of the bushing member.
Other features and benefits that characterize embodiments of the present invention will be apparent upon reading the following detailed description and review of the associated drawings.